FUELG-C-01AUG01-MT-LI UC Davis Prof Andrew Frank collects data from the new electronics installed into a 1994 mercury Sable that's now a hybride car, running on both electricity and a smaller gas engine than originally installed my the manufacture. By LANCE IVERSEN/SAN FRANCISCO CHRONICLE Ran on: 04-24-2005
Professor Andrew Frank of UC Davis collects data from a 1994 Mercury Sable that he and students converted to a hybrid car.

It seems like the best of both worlds, assuming one world is pure electric and the other is hybrid.

It is called "plug-in hybrid," and it's the latest popular wrinkle among the alternative fuel cognoscenti. They're the folks who believe that ideally we should all be driving pure electric cars, but short of that, we should capitalize on the electric portion of a hybrid as much as possible.

In simple terms, what they have in mind is plugging in your hybrid to your home's electric power supply at night. The next morning, the first 10, 20 or even 60 miles would be driven solely on electricity, rather than the combination of electric motor and gas-powered engine that propels hybrids now on the market.

Car companies, with the exception of DaimlerChrysler, have been, if not cool, at least neutral on the subject of plug-ins. They're still concentrating on developing a fuller product line of the hybrids.

"The bigger the electric motor and the smaller the gas engine, the more efficient the overall vehicle is," Frank said.

Three years ago, he and his students converted a standard Mercury Sable to plug-in hybrid using a small four-cylinder gas engine and a 100-horsepower electric motor. After an overnight charge, the car could go 60 miles on its electric motor.

The average U.S. driver goes about 38 miles a day, the federal government says. Frank thinks most of that could be done only on the electric part of the hybrid equation.

"We'd go to a gas station about five times a year, as opposed to 35 times a year with a conventional car," Frank said.

Two years ago, DaimlerChrysler joined with Palo Alto's Electric Power Research Institute, a nonprofit funded by the nation's utilities, to build a handful of plug-in hybrid-powered delivery vans. One van is already running on German streets; Bob Graham, the institute's program manager for sustainable technologies, says four more will come to the United States in June for testing.

"We hope there's a strong enough case to justify this becoming a full- time product," Graham said, "and then (we can) migrate it into the mass customer market."